This disclosure relates generally to a gearing assembly that rotatably couples a prime mover and a motor-generator.
Prime movers, such as turbomachines, are known. A typical turbomachine includes a fan section, a compression section, a combustor section, and a turbine section. Turbomachines have at least one rotor in the compression section. The rotor must be accelerated to a relatively high rotational speed until the rotor is rotating fast enough to sustain operation of the turbomachine.
A motor-generator, separate from the turbomachine, is used as a motor to rotate the rotor during start-up of the turbomachine. After the turbomachine is self-sustaining, the motor-generator is used as a generator and driven by the turbomachine.
The rotational speeds of prime movers may be different than the optimal speed of the motor-generator. Also, the rotational speeds vary considerably during operation, and it is desirable to provide the motor-generator with a rotational input that is relatively consistent. Hydro-mechanical transmissions are thus used to step-up or step-down rotation between the prime mover and the motor-generator. The size and weight of the hydro-mechanical transmissions must increase to accommodate larger ranges of rotational speeds.